Electron energy balance and MHD modelling of the conduction phase in a plasma opening switch

Summary form only given. Inductive energy storage devices, utilizing the fast opening of a plasma opening switch (POS), may generate high power (>1 TW) and short duration (<0.1 /spl mu/S) pulses, ideal for driving intense beam diodes or z-pinches. The use of high-density plasma switches (10/sup 15/ to 10/sup 16/ cm/sup -3/) has allowed an extension of the conduction time to above 1 /spl mu/s while still allowing a rapid opening time (few tens of ns). Understanding of the POS plasma redistribution and thinning (in preparation for opening) during the conduction phase can be acquired via magneto-hydrodynamic (MHD) modeling and simulation. In an effort to extend the validity of MHD methods into low-density regimes (switch opening) where space-charge separation and kinetic effects are expected to play a key role, we are required to incorporate the Hall and thermoelectric effects into generalized Ohm´s Law. We will discuss the subtle non-linear coupling between MHD, Hall, thermoelectric, and resistively diffusive processes in POS plasmas during the conduction phase. Specifically, the dependence and influence of these processes on electron temperature profiles in the plasma requires a detailed electron energy balance before accurate MHD simulations of POS plasmas can be performed, Improved methods for thermal conduction in a strong magnetic field, electron energy convection in current channels, and radiation cooling in POS plasmas will be presented, including some preliminary MHD simulation results.